President Bush, NOW is the time!
No, not yet. Syria and Iran have (foolishly, IMO) shown their intentions to back Lebanon. Muslim machismo dictates that they follow through with their threats, but they know that the US will stomp their @sses into the ground if they make a move towards Israel. The US can't join the fray until they make a move, otherwise we're seen as the aggressor. It all adds up to Israel stomping the crap out of Hezbollah and Hamas while Syria and Iran watch in frustration.
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To join the war? You're nuts. This isn't America's war, Israel can defend itself just fine on its own, especially cause it has mostly U.S. weapons and intelligence.